Cationic dyestuffs,mixtures thereof and their use in dyeing fibers based on acrylonitrile



United States Patent Q 3,459,489 CATIGNIC DYESTUFFS, MIXTURES THEREOF AND THEIR USE 1N DYETNG FIBERS BASED ON ACRYLONITRHLE Robert Frederic Michel Sureau, Enghien-les-Bains, and Marie .losephe Jeanne Aiicot, Soisy-sous-Montmorency, France, assignors to Ugine Kuhlmaun, Paris, France No Drawing. (Iontiuuation-in-part of application Ser. No. 541,501, Apr. 11, 1966. This application .luly 5, 1967, Ser. No. 651,158 Claims priority, application France, Apr. 13, 1965, 13,041; Aug. 4, 1966, 72,028 Int. Cl. Dilp 3/70 US. Cl. 8-25 11 (Ilaims ABSTRACT OF THE DISCLOSURE Cationic dyestufis of the general formula:

M i i A 2 7 l 8 wherein the naphthalene nucleus A may be unsubstituted or substituted by one or two chlorine or bromine atoms, one or two hydroxy groups, or one or two OY groups in which Y represents an alkyl,.aralkyl or aryl group, the benzene nucleus B may be unsubstituted or substituted by one or more chlorine or bromine atoms or methyl, nitrile, trifluoromethyl or O-Y groups, at least one of the nuclei A and B being substituted, R represents an alkyl or aralkyl group and X represents a monovalent anion.

Also mixtures of such cationic dyestuffs, their use in dyeing and fibres based on polymers or copolymers of acrylonitrile dyed with the dyestufis or the mixtures thereof.

in which the naphthalene nucleus A may be substituted by one or two chlorine or bromine atoms, one or two hydroxy groups or one or two OY groups, Y representing an alkyl, aralkyl or aryl group, preferably methyl or ethyl, the benzene nucleus B may be substituted by one or more chlorine or bromine atoms, or methyl, nitrile, trifiuoromethyl or OY groups (Y having the same significance as above), at least one of the nuclei A and B being substituted, R represents an alkyl or aralkyl group and X represents a monovalent anion.

The invention includes mixtures of these dyestuffs.

The dyestuffs of the invention are new and they may be obtained, for example, by treatment at a temperature from C. to C. inclusive of naphthoylene-benzimidazole derivatives of the formula:

in which the substituents of A and B are as defined above, with alkylating agents, possibly in the presence of an organic solvent, according to known methods such as described in US. Patent No. 2,893,816.

The alkylating agents that may be used include, in particular, the alkyl halides, sulphates and aryl-sulphonates. The organic solvents that may be used especially include alcohols, chloroform, benzene hydrocarbons and their chlorinated derivatives and dimethyl formamide. It may be necessary to work under pressure, for example, when the boiling point of the alkylating agent is lower than 100 C.

The dyestufis of Formula I are generally very soluble in water, even cold water. In order to separate them it may be advantageous to precipitate them as complex salts, for example by the addition of zinc chloride to their aqueous solutions.

The dyestuffs of Formula Il may be prepared in a known manner by the condensation of naphthalic anhydride or its substituted derivatives with o-phenylenediamine or its substituted derivatives. It is also known that in the case substituted derivatives, the dyestufi of Formula II obtained is generally a mixture of isomers. With a view to preparing the dyestufis of Formula I one can use mixtures of isomers of Formula II and mixtures of isomers of dyestuffs of Formula I are thus obtained. In order to obtain dyestuffs of Formula I which are practically free of isomers, unitary dyestuffs of Formula II can be used, which may be obtained-either by separation of a mixture of isomers, for example by fractional crystallisation, or by an unambiguous synthesis such as for example the condensation of naphthalic anhydride with a substituted ortho nitraniline, then reduction of the nitro group and cyclisation, these last two phases being able to be carried out simultaneously.

The dyestuffs of Formula I possess the general properties of cationic dyestuffs and they dye fibres based on polymers or copolymers of acrylonitrile in full-bodied yellow shades endowed with exceptional brilliance and good general fastness. Dyestuffs which are particularly fast to light are those containing an alkoxy group in the 5 position and these may be obtained from a 5-alkoxy-2- nitro-aniline. As compared with the dyestuffs according to the invention, naphthoylene-benzimidazolium salts which are not substituted on one of the nuclei A or B are of no practical interest because their tinctorial power is too small.

In the following examples, which are purely illustrative, to which the invention is not limited, the parts are parts by weight unless the contrary is indicated,

3 EXAMPLE 1 15 parts of methoxynaphthoylenebenzimidazole (in fact a mixture of the 4- and -isomers), obtained by condensing 4-methoxy-1,2-phenylenediamine with naphthalic anhydried in acetic medium, are heated for one and a half hours at 110-115 C. in 45 parts of dime'thyl sulphate. The solution obtained is allowed to cool to 80 C. and then poured into about 150 parts of water. The mixture is stirred for several hours at 6080 C. until compelte hydrolysis of the excess methyl sulphate has occurred, 40 parts of sodium chloride are added and then a concentrated solution of zinc chloride in an amount such that the mother liquors are practically decolorised. The product is left to cool, the solid filtered off, washed with a 5% solution of sodium chloride, drained and dried in an oven. 16 parts of a yellow dyestulf are obtained which dyes fibers based on polymers of copolymers of acrylonitrile a vivid and brilliant green-yellow shade endowed with excellent general fastness.

In the following table are grouped a number of examples of dyestuffs according to the invention, which have been prepared in a similar way. Isomers are obtained in admixture.

Shade on acrylic Ex. Substituents of A S ubstituents of B fibres 2 3-(or 6-)-hydr0xy 4-(0r 5-)-metl1oxy- Green yellow. 3 3,6-dihydroxy .do Do. 4 3-(0r 6-)-methoxy .do Do. 5 3, dimethoxy .ado Yellow. 6 3,6-dimethoxy-4-(or do Golden 5-)-bromo. yellow. 7 4-(or 5-)-broruo do Do. 8 4-(or 5-)-ehloro .do Yellow. 9 3-(0r 6-)-l1ydroxy 4-(or 5-)-chloro Green yellow. 10. 3,6dihydroxy Do. 11 3- r 6)-methoxy. 12. 3,6-dimethoxy 13 3,6-dimethoxy-4(or 5-)-bromo. 14 4-(or 5-)-bromo do Green yellow. 15 3-(or 6)-hydroxy 4-(or 5-)-methyl D 0.

EXAMPLE 16 A mixture of 21 parts of methoxynaphthoylenebenzimidazole (obtained as in Example 1), 150 parts by volume of methanol and parts by volume of methyl iodide is heated at 180 C. for two hours in an autoclave. After cooling, the methoxynaphthoylenemethylbenzimidazolium iodide crystals formed are filtered off and washed with a little methanol. The precipitate is redissolved in the necessary amount of boiling water, a little active charcoal is added, the solution is filtered while hot and the filtrate left to cool. After filtration and drying of the precipitate, 13 parts of a dyestutf having the same tinctorial properties as the dyestuff described in Example 1 are obtained.

EXAMPLE 17 A mixture of parts of methoxynaphthoylenebenzimidazole (obtained as in Example 1) and 12.5 parts of the methyl ether of p-toluene-sulphonic acid is heated at 110-115 C. for one and a half hours. 110 parts by volume of toluene are added, the mixture is left to cool, and the precipitate obtained is filtered off, washed with ether and then dissolved in 150 parts of boiling water. A little active charcoal is added to the solution, the latter is filtered and parts of sodium chloride and a quantity of a concentrated solution of zinc chloride such that the mother liquor is practically decolorised are added to the filtrate. The solid is filtered off, drained and dried in an oven. The dyestutf obtained has tinctorial properties identical with those of the dyestulf described in Example 1.

EXAMPLE 18 A mixture of 100 parts of 2-nitro-5-chloro-aniline, 600 parts by volume of methanol and 36 parts of caustic potash are heated at 120140 C, for 5 hours. After cooling, the crystalline 2-nitro-S-methoxy-aniline, mixed with potassium chloride, is filtered off, washed with water and dried at C. Dry Weight obtained: 67 to 68 parts. Melting point: 127128 C. When concentrated to a quater of their volume, the mother liquors give up a second fraction which may be recrystallised from methanol. Dry weight obtained: 5 to 6 parts, that is, a total yield of about 75%.

A mixture of 31.2 parts of naphthalic anhydride and 25.2 parts of 2-nitro-5-methoxy-aniline is heated at 240 C. to 250 C. for 4 hours. The molten mass is poured on a plate. After cooling, the solidified product is ground and taken up twice in boiling alcohol, then twice in a dilute solution of sodium carbonate. The solid is filtered off and washed with water. The dried product is recrystallised in about 60 parts of dimethyl formamide, from which 2 nitro 5 methoxy-phenylnaphthoylimide crystallises on cooling. The filtered product is washed with water and dried, and melts at 233 C. (Maquenne block). The dilute filtrate gives up a second fraction rather less pure, M.P. 222225 C. Total dry weight: 40 parts.

36 parts of this product are introduced in small fractions in a period of about an hour into a mixture of 75 parts of powdered iron, parts of water and 15 parts of acetic acid which had previously been boiled for a few moments and vigorously agitated. The mixture is heated under reflux for about 14 hours. The mass is then neutralised with 15 parts of anhydrous sodium carbonate, and the sludge of iron hydroxide containing the 5'-methoxy-naphthoylenebenzimidazole formed is filtered off, drained and dried. The dyestuif is extracted with chlorobenzene, the chlorobenzene is removed with steam, and the aqueous suspension of the dyestuff is filtered. The dyestuif is in the form of a yellow powder melting at 210 C. to 212 C. Dry weight obtained: 23 parts.

These 23 parts are dissolved in 310 parts by volume of dry chlorobenzene. The solution is heated under gentle reflux and 17 parts by volume of methyl sulphate dilute with an equal volume of chlorobenzene are introduced in a period of one hour. Heating under reflux is continued for an hour, and the product is allowed to cool and the precipitate of 5-methoxy-naphthoylene-benzimidazolium methyl sulphate formed is filtered off, washed with chlorobenzene, drained and dried. Dry weight obtained: 30 to 31 parts of a dyestuff which dyes fibres based on polyacrylonitrile in green yellow shades of great brilliance and having excellent fastness, especially to light.

EXAMPLE 19 On replacing the 2-nitro-5-methoxy-aniline used in the condensation with naphthalic anhydride in Example 18, with 27.3 parts of 2-nitro-S-ethoxy-aniline, and complet ing the operation under similar conditions, S-ethoxynaphthoylenebenzimidazolium methyl sulphate is finally obtained, the tinctorial properties of which are very close to those of the dyestufi" of Example 18.

EXAMPLE 20 A mixture of 10 parts of naphthalic anhydride, 11 parts of 4-methoxy-1,Z-phenylenediamine sulphate (titrating 66% of free diamine) and 6 parts of anhydrous sodium acetate is boiled for 4 hours under reflux.

The product is allowed to cool and to stand for several hours, then the precipitate is filtered off, washed with alcohol and then with water until the sulphate ions are eliminated. After drying, 13.5 parts of an isomeric mixture of 4-methoxyand 5-methoxy-naphthoylene-benzimidazole melting at 166-16S C. are obtained.

After three recrystallisations from glacial acetic acid at the rate of 1 part of dyestuff to 10 parts of acetic acid, 4-methoxy-naphthoylenebenzimidazole is finally obtained in the pure state melting at 194 C.

On treating this dyestutf with methyl sulphate under wherein the naphthalene nucleus A may be unsubstituted or substituted by one or two chlorine or bromine atoms, or one or two hydroxy or OY groups in which Y represents an alkyl, aralkyl or aryl group, the benzene nuccleus B may be unsubstituted or substituted by one or more chlorine or bromine atoms or methyl, nitrile, trifluoromethyl or OY groups, at least one of the nuclei A and B being substituted, R represents an alkyl or aralkyl group and X represents a monovalent anion.

2. Dyestuffs and mixtures of dyestuffs as claimed in claim 1 wherein Y represents a methyl or ethyl group.

3. 5-methoxyand 5'-ethoxy-naphthoylene-benzimid azolium salts.

4. 4-methoxy-naphthoylenebenzimidazolium salts.

5. N-methyl-5'-methoxy naphthoylene-benzimidazolium methylsulphate.

6. Mixtures of N methyl naphthoylene benzimidazolium salts as claimed in claim 1 in which the quaternised dyestuffs are the condensation products of 4-methoxy-1,2-phenylenediamine with the anhydride of 3,6-dihydroxy-naphthalene-1,8-dicarboxylic acid.

7. Mixtures of N -methyI naphthoylene-benzimidazolium salts as claimed in claim 1 in which the quaternised dyestufls are the condensation products of 4-methoxy-1,2- phenylenediamine with the anhydride of 3-methoxynaphthalene-1,8-dicarboxylic acid.

8. Mixtures of N -methyl naphthoylene-benzimidazolium salts as claimed in claim 1 in which the quaternised dyestuffs are the condensation products of 4-methoxy- 1,2-phenylenediamine with the anhydride of 3,6-dimethoxy-naphthalene-1,8-dicarboxylic acid.

9. Mixtures of N -methyl naphthoylene-benzimidazolium salts as claimed in claim 1 in which the quaternised dyestuffs are the condensation products of 4-methoxy- 1,2-phenylenediamine with the anhydride of naphthalenel,8-dicarboxylic acid.

10. Mixtures of N -methyl naphthoylene-benzimidazolium salts as claimed in claim 1 in which the quaternised dyestufis are the condensation products of 4-ch1oro-l,2-phenylenediamine with the anhydride of 3,6-dimethoxy-naphthalene-1,8-dicarboxylic acid.

11. Fibres based on polymers or copolymers of acrylonitrile dyed with a dyestuff or mixture of dyestuffs as claimed in claim 1.

References Cited UNITED STATES PATENTS 2,994,697 8/1961 Eckert et a1. 260282 3,103,403 9/1963 Eaton et a1. 8-55 FOREIGN PATENTS 1,251,445 12/ 1960 France.

NORMAN G. TORCHIN, Primary Examiner T. J. HERBERT, 111., Assistant Examiner US. Cl. XR. 8-55; 260-482 

